How do you keep seahorses?

Most seahorses that are sold to for aquariums are bred in captivity so it doesn't impact the wild seahorses as much. Wild seahorses are also harder to keep alive because they are pickier about their food,

The other trade that uses seahorses is Chinese medicine. I don't know for sure, if those are wild caught or captive bred but I would imagine that captive breeding would be more cost effective.